Ophthalmic compositions for treating ocular hypertension

ABSTRACT

This invention relates to the use of potent potassium channel blockers or a formulation thereof in the treatment of glaucoma and other conditions which leads to elevated intraoccular pressure in the eye of a patient. This invention also relates to the use of such compounds to provide a neuroprotective effect to the eye of mammalian species, particularly humans.

BACKGROUND OF THE INVENTION

Glaucoma is a degenerative disease of the eye wherein the intraocularpressure is too high to permit normal eye function. As a result, damagemay occur to the optic nerve head and result in irreversible loss ofvisual function. If untreated, glaucoma may eventually lead toblindness. Ocular hypertension, i.e., the condition of elevatedintraocular pressure without optic nerve head damage or characteristicglaucomatous visual field defects, is now believed by the majority ofophthalmologists to represent merely the earliest phase in the onset ofglaucoma.

Many of the drugs formerly used to treat glaucoma proved unsatisfactory.The early methods of treating glaucoma employed pilocarpine and producedundesirable local effects that made this drug, though valuable,unsatisfactory as a first line drug. More recently, clinicians havenoted that many β-adrenergic antagonists are effective in reducingintraocular pressure. While many of these agents are effective for thispurpose, there exist some patients with whom this treatment is noteffective or not sufficiently effective. Many of these agents also haveother characteristics, e.g., membrane stabilizing activity, that becomemore apparent with increased doses and render them unacceptable forchronic ocular use and can also cause cardiovascular effects.

Although pilocarpine and β-adrenergic antagonists reduce intraocularpressure, none of these drugs manifests its action by inhibiting theenzyme carbonic anhydrase, and thus they do not take advantage ofreducing the contribution to aqueous humor formation made by thecarbonic anhydrase pathway.

Agents referred to as carbonic anhydrase inhibitors decrease theformation of aqueous humor by inhibiting the enzyme carbonic anhydrase.While such carbonic anhydrase inhibitors are now used to treatintraocular pressure by systemic and topical routes, current therapiesusing these agents, particularly those using systemic routes are stillnot without undesirable effects. Because carbonic anhydrase inhibitorshave a profound effect in altering basic physiological processes, theavoidance of a systemic route of administration serves to diminish, ifnot entirely eliminate, those side effects caused by inhibition ofcarbonic anhydrase such as metabolic acidosis, vomiting, numbness,tingling, general malaise and the like. Topically effective carbonicanhydrase inhibitors are disclosed in U.S. Pat. Nos. 4,386,098;4,416,890; 4,426,388; 4,668,697; 4,863,922; 4,797,413; 5,378,703,5,240,923 and 5,153,192.

Prostaglandins and prostaglandin derivatives are also known to lowerintraocular pressure. U.S. Pat. No. 4,883,819 to Bito describes the useand synthesis of PGAs, PGBs and PGCs in reducing intraocular pressure.U.S. Pat. No. 4,824,857 to Goh et al. describes the use and synthesis ofPGD2 and derivatives thereof in lowering intraocular pressure includingderivatives wherein C-10 is replaced with nitrogen. U.S. Pat. No.5,001,153 to Ueno et al. describes the use and synthesis of13,14dihydro-15-keto prostaglandins and prostaglandin derivatives tolower intraocular pressure. U.S. Pat. No. 4,599,353 describes the use ofeicosanoids and eicosanoid derivatives including prostaglandins andprostaglandin inhibitors in lowering intraocular pressure.

Prostaglandin and prostaglandin derivatives lower intraocular pressureby increasing uveoscleral outflow. This is true for both the F type andA type of Pgs and hence presumably also for the B, C, D, E and J typesof prostaglandins and derivatives thereof. A problem with usingprostaglandin derivatives to lower intraocular pressure is that thesecompounds often induce an initial increase in intraocular pressure, canchange the color of eye pigmentation and cause proliferation of sometissues surrounding the eye.

As can be seen, there are several current therapies for treatingglaucoma and elevated intraocular pressure, but the efficacy and theside effect profiles of these agents are not ideal. Recently potassiumchannel blockers were found to reduce intraocular pressure in the eyeand therefore provide yet one more approach to the treatment of ocularhypertension and the degenerative ocular conditions related thereto.Blockage of potassium channels can diminish fluid secretion, and undersome circumstances, increase smooth muscle contraction and would beexpected to lower IOP and have neuroprotective effects in the eye. (seeU.S. Pat. Nos. 5,573,758 and 5,925,342; Moore, et al., Invest.Ophthalmol. Vis. Sci 38, 1997; WO 89/10757, W094/28900, and WO96/33719).

SUMMARY OF THE INVENTION

This invention relates to the use of potent potassium channel blockersor a formulation thereof in the treatment of glaucoma and otherconditions that are related to elevated intraocular pressure in the eyeof a patient. This invention also relates to the use of such compoundsto provide a neuroprotective effect to the eye of mammalian species,particularly humans. More particularly this invention relates to thetreatment of glaucoma and/or ocular hypertension (elevated intraocularpressure) using novel indole compounds having the structural formula I:

or a pharmaceutically acceptable salt, enantiomer, diastereomer ormixture thereof:

-   -   wherein,    -   R represents hydrogen, or C₁₋₆ alkyl;    -   R₁ represents hydrogen or C₁₋₆ alkyl, CF₃, C₁₋₆ alkoxy, COR^(c),        CO₂R₈, CONHCH₂CO₂R, N(R)₂, said alkyl and alkoxy optionally        substituted with 1-3 groups selected from R^(b);    -   X represents —(CHR₇)_(p)—;    -   Y is not present, —CO(CH₂)_(n)—, or —CH(OR)—;    -   Q represents N, CR^(y), or O, wherein R₂ is absent when Q is O;    -   R^(y) represents H, or C₁₋₆ alkyl;    -   R_(w) represents H, C₁₋₆ alkyl, —C(O)C₁₋₆ alkyl, —C(O)OC₁₋₆        alkyl, —SO₂N(R)₂, —SO₂C₁₋₆ alkyl, —SO₂C₆₋₁₀ aryl, NO₂, CN or        —C(O)N(R)₂;    -   R₂ represents hydrogen, C₁₋₁₀ alkyl, C₁₋₆ alkylSR,        —(CH₂)_(n)O(CH₂)_(m)OR, —(CH₂)_(n)C₁₋₆ alkoxy, —(CH₂)_(n)C₃₋₈        cycloalkyl, —(CH₂)_(n)C₃₋₁₀ heterocyclyl, —(CH₂)_(n)C₅₋₁₀        heteroaryl, —N(R)₂, —COOR, or —(CH₂)_(n)C₆₋₁₀ aryl, said alkyl,        heterocyclyl, aryl or heteroaryl optionally substituted with 1-3        groups selected from R^(a);    -   R₃ represents hydrogen, C₁₋₁₀ alkyl, —(CH₂)_(n)C₃₋₈ cycloalkyl,        —(CH₂)_(n)C₃₋₁₀ heterocyclyl, —(CH₂)_(n)C₅₋₁₀ heteroaryl,        —(CH₂)_(n)COOR, —(CH₂)_(n)C₆₋₁₀ aryl, —(CH₂)_(n)NHR₈,        —(CH₂)_(n)N(R)₂, —(CH₂)_(n)NHCOOR, —(CH₂)_(n)N(R₈)CO₂R,        —(CH₂)_(n)N(R₈)COR, —(CH₂)_(n)NHCOR, —(CH₂)_(n)CONH(R₈), aryl,        —(CH₂)_(n)C₁₋₆ alkoxy, CF₃, (CH₂)_(n)SO₂R, —(CH₂)_(n)SO₂N(R)₂,        —(CH₂)_(n)CON(R)₂, —(CH₂)_(n)CONHC(R)₃, —(CH₂)_(n)COR₈, nitro,        cyano or halogen, said alkyl, alkoxy, heterocyclyl, aryl or        heteroaryl optionally substituted with 1-3 groups of R^(a);    -   or, when Q is N, R₂ and R₃ taken together with the intervening N        atom form a 4-10 membered heterocyclic carbon ring optionally        interrupted by 1-2 atoms of O, S, C(O) or NR, and optionally        having 1-4 double bonds, and optionally substituted by 1-3        groups selected from R^(a);    -   R⁴ and R⁵ independently represent hydrogen, C₁₋₆ alkoxy, OH,        C₁₋₆ alkyl, COOR, SO₃H, O(CH₂)_(n)N(R)₂, O(CH₂)_(n)CO₂R, C₁₋₆        alkylcarbonyl, S(O)qR^(y), OPO(OH)_(2,) CF₃, N(R)₂, nitro, cyano        or halogen;    -   R₆ represents hydrogen, C₁₋₁₀ alkyl, —(CH₂)_(n)C₆₋₁₀ aryl,        —(CH₂)_(n)C₅₋₁₀ heteroaryl, (C₆₋₁₀ aryl)O—, —(CH₂)_(n)C₃₋₁₀        heterocyclyl, —(CH₂)_(n)C₃₋₈ cycloalkyl, —COOR, —C(O)CO₂R, said        aryl, heteroaryl, heterocyclyl and alkyl optionally substituted        with 1-3 groups selected from R^(a);    -   R⁷ represents hydrogen, C₁₋₆ alkyl, —(CH₂)_(n)COOR or        —(CH₂)_(n)N(R)₂,    -   R⁸ represents —(CH₂)_(n)C₃₋₈ cycloalkyl, —(CH₂)_(n 3-10)        heterocyclyl, C₁₋₆ alkoxy or —(CH₂)_(n)C₅₋₁₀ heteroaryl, said        heterocyclyl, aryl or heteroaryl optionally substituted with 1-3        groups selected from R^(a);    -   R^(a) represents F, Cl, Br, I, CF₃, N(R)₂, NO₂, CN, —COR₈,        —CONHR₈, —CON(R₈)₂, —O(CH₂)_(n)COOR, —NH(CH₂)_(n)OR, —COOR,        —OCF₃, —NHCOR, —SO₂R, —SO₂HR₂, —SR, (C₁-C₆ alkyl)O—,        —(CH₂)_(n)O(CH₂)_(m)OR, —(CH₂)_(n)C₁₋₆ alkoxy, (aryl)O—, —OH,        (C₁-C₆ alkyl)S(O_(m)—, H₂N—C(N)—, (C₁-C₆ alkyl)C(O)-, (C₁₋₆        alkyl)OC(O)NH—, —(C₁-C₆ alkyl)NR_(w)(CH₂)_(n)C₃₋₁₀        heterocyclyl-R_(w), —(C₁-C₆ alkyl)O(CH₂)_(n)C₃₋₁₀        heterocyclyl-R_(w), —(C₁-C₆ alkyl)S(CH₂)_(n)C₃₋₁₀        heterocyclyl-R_(w), —(C₁-C₆ alkyl)-C₃₋₁₀ heterocyclyl-R_(w),        —(CH₂)_(n)-Z¹-C(=Z²)N(R)₂, —(C₂₋₆ alkenyl)NR_(w)(CH₂)_(n)C₃₋₁₀        heterocyclyl-R_(w), —(C₂₋₆ alkenyl)O(CH₂)_(n)C₃₋₁₀        heterocyclyl-R_(w), —(C₂₋₆ alkenyl)S(CH₂)_(n)C₃₋₁₀        heterocyclyl-R_(w), —(C₂₋₆ alkenyl)-C₃₋₁₀ heterocyclyl-R_(w),        —(C₂₋₆ alkenyl)-Z¹-C(=Z²)N(R)₂, —(CH₂)_(n)SO₂R, —(CH₂)_(n)SO₃H,        —(CH₂)_(n)PO(OR)₂, cyclohexyl, morpholinyl, piperidyl,        pyrrolidinyl, thiophenyl, phenyl, pyridyl, imidazolyl, oxazolyl,        isoxazolyl, thiazolyl, thienyl, furyl, isothiazolyl, C₂₋₆        alkenyl, and C₁-C₁₀ alkyl, said alkyl, alkenyl, alkoxy, phenyl,        pyridyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, thienyl,        furyl, and isothiazolyl optionally substituted with 1-3 groups        selected from C₁-C₆ alkyl, COOR, SO₃H, OH, F, Cl, Br, I,        —O(CH₂)_(n)CH(OH)CH₂SO₃H, and    -   Z¹ and Z² independently represents NR_(w), O, CH₂, or S;    -   R^(b) represents C₁₋₆ alkyl, —COOR, —SO₃R, —OPO(OH)₂,        —(CH₂)_(n)C₆₋₁₀ aryl, or —(CH₂)_(n)C₅₋₁₀ heteroaryl;    -   R^(c) represents hydrogen, C₁₋₆ alkyl, or —(CH₂)_(n)C₆₋₁₀ aryl;    -   m is 0-3;    -   n is 0-3;    -   q is 0-2; and    -   p is 0-1.

This and other aspects of the invention will be realized upon inspectionof the invention as a whole.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to novel potassium channel blockers ofFormula I. It also relates to a method for decreasing elevatedintraocular pressure or treating glaucoma by administration, preferablytopical or intra-camaral administration, of a composition containing apotassium channel blocker of Formula I described hereinabove and apharmaceutically acceptable carrier.

One embodiment of this invention is realized when X is CHR₇.

One embodiment of this invention is realized when Y is —CO(CH₂)_(n) andall other variables are as originally described. A subembodiment of thisinvention is realized when n is 0.

Another embodiment of this invention is realized when Y is CH(OR) andall other variables are as originally described.

Still another embodiment of this invention is realized when Q is N andall other variables are as originally described.

Still another embodiment of this invention is realized when Q is CH andall other variables are as originally described.

In another embodiment R_(w) is selected from H, C₁₋₆ alkyl, —C(O)C₁₋₆alkyl and —C(O)N(R)₂.

Still another embodiment of this invention is realized when R₆ is(CH₂)_(n)C₆₋₁₀ aryl, (CH₂)_(n)C₅₋₁₀ heteroaryl, (CH₂)_(n)C₃₋₁₀heterocyclyl, or (CH₂)_(n)C₃₋₈ cycloalkyl, said aryl, heteroaryl,heterocyclyl and cycloalkyl optionally substituted with 1 to 3 groups ofR^(a), and all other variables are as originally described.

Yet another embodiment of this invention is realized when R₆ is(CH₂)_(n)C₆₋₁₀ aryl, (CH₂)_(n)C₅₋₁₀ heteroaryl or (CH₂)_(n)C₃₋₁₀heterocyclyl, said aryl, heteroaryl and heterocyclyl optionallysubstituted with 1 to 3 groups of R^(a), and all other variables are asoriginally described.

Yet another embodiment of this invention is realized when R⁷ is hydrogenor C₁₋₆ alkyl, and all other variables are as originally described.

Yet another embodiment of this invention is realized when Y is—CO(CH₂)_(n), and Q is N. A subembodiment of this invention is realizedwhen n is 0.

Still another embodiment of this invention is realized when Y is—CO(CH₂)_(n), Q is N, R₂ is C₁₋₁₀ alkyl or C₁₋₆ alkylOH and R₃ is(CH₂)_(n)C₃₋₁₀ heterocyclyl, said heterocyclyl and alkyl optionallysubstituted with 1 to 3 groups of R^(a). A subembodiment of thisinvention is realized when n is 0.

Still another embodiment of this invention is realized when R₂ and R₃are taken together with the intervening N atom form a 4-10 memberedheterocyclic carbon ring optionally interrupted by 1-2 atoms of O, S,C(O) or NR, and optionally having 1-4 double bonds, and optionallysubstituted by 1-3 groups selected from R^(a); Examples of saidheterocyclic groups are:

and the like.

Another embodiment of the instant invention is realized when R^(a) isselected F, Cl, Br, I, CF₃, N(R)₂, NO₂, CN, —CONHR₈, —CON(R₈)₂,—O(CH₂)_(n)COOR, —NH(CH₂)_(n)OR, —COOR, —OCF₃, —NHCOR, —SO₂R, —SO₂NR₂,—SR, (C₁-C₆ alkyl)O—, —(CH₂)_(n)O(CH₂)_(m)OR, —(CH₂)_(n)C₁₋₆ alkoxy,(aryl)O—, —OH, (C₁-C₆ alkyl)S(O)_(m)—, H₂N—C(NH)—, (C₁-C₆ alkyl)C(O)—,(C₁-C₆ alkyl)OC(O)NH—, —(C₁-C₆ alkyl)NR_(w)(CH₂)_(n)C₃₋₁₀heterocyclyl-R_(w), —(CH₂)_(n)-Z¹-C(=Z²)N(R)₂, —(C₂₋₆alkenyl)NR_(w)(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w),—(C₂₋₆alkenyl)-Z¹-C(=Z²)N(R)₂,—(CH₂)_(n)SO₂R, —(CH₂)_(n)SO₃H,—(CH₂)_(n)PO(OR)₂, C₂₋₆ alkenyl, and C₁-C₁₀ alkyl, said alkyl andalkenyl, optionally substituted with 1-3 groups selected from C₁-C₆alkyl, and COOR;

Compounds to be used in this invention are represented by Tables 1-14TABLE 1

Wherein R represents:

and R* represents:

TABLE 2

Wherein R represents:

R* represents:

and R{circumflex over ( )} represents hydrogen or methyl

TABLE 3

Wherein R represents:

R* represents:

and R{circumflex over ( )} represents hydrogen or methyl;

TABLE 4

R represents methyl or methoxy and R* represents methyl or COOH;

R′ represents methyl or methoxy; R{circumflex over ( )} representshydrogen or COOEt; R′″ represents COOH or COOtBu; and R″ represents:COOMe, COOH, or

TABLE 5

R* represents hydrogen or methyl; R^(y) represents methyl or CF₃; Rrepresents methyl, (CH2)₂SCH₃,

R{circumflex over ( )} represents:

R+ represents: (CH₂)₂CO₂H, chlorine,

TABLE 6

Wherein n represents 1-2; R{circumflex over ( )} represents hydrogen ormethyl R represents:

and R′ represents: chlorine,

or a pharmaceutically acceptable salt, enantiomer, diastereomer ormixture thereof.

Other examples of this invention are illustrated in tables 7-14: TABLE 7

R is:

TABLE 8

R is:

TABLE 9

R is:

TABLE 10

R is:

TABLE 11

Wherein R represents:

R₁ represents:

R2 represents: hydrogen or methyl or a pharmaceutically acceptable salt,enantiomer, diastereomer or mixture thereof.

TABLE 12

Wherein R represents:

R₁ represents:

R2 represents: hydrogen or methyl

TABLE 13

TABLE 14

or a phannaceutically acceptable salt, enantiomer, diastereomer ormixture thereof.

The invention is described herein in detail using the terms definedbelow unless otherwise specified.

The compounds of the present invention may have asymmetric centers,chiral axes and chiral planes, and occur as racemates, racemic mixtures,and as individual diastereomers, with all possible isomers, includingoptical isomers, being included in the present invention. (See E. L.Eliel and S. H. Wilen Stereochemistry of Carbon Compounds (John Wileyand Sons, New York 1994), in particular pages 1119-1190)

When any variable (e.g. aryl, heterocycle, R¹, R⁶ etc.) occurs more thanone time in any constituent, its definition on each occurrence isindependent at every other occurrence. Also, combinations ofsubstituents/or variables are permissible only if such combinationsresult in stable compounds.

The term “alkyl” refers to a monovalent alkane (hydrocarbon) derivedradical containing from 1 to 10 carbon atoms unless otherwise defined.It may be straight, branched or cyclic. Preferred alkyl groups includemethyl, ethyl, propyl, isopropyl, butyl, t-butyl, cyclopropylcyclopentyl and cyclohexyl. When the alkyl group is said to besubstituted with an alkyl group, this is used interchangeably with“branched alkyl group”.

Cycloalkyl is a specie of alkyl containing from 3 to 15 carbon atoms,unless otherwise defined, without alternating or resonating double bondsbetween carbon atoms. It may contain from 1 to 4 rings, which are fused.Examples of such cycloalkyl elements include, but are not limited to,cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.

Alkoxy refers to an alkyl group of indicated number of carbon atomsattached through an oxygen bridge, with the alkyl group optionallysubstituted as described herein. Said groups are those groups of thedesignated length in either a straight or branched configuration and iftwo or more carbon atoms in length, they may include a double or atriple bond. Exemplary of such alkoxy groups are methoxy, ethoxy,propoxy, isopropoxy, butoxy, isobutoxy, tertiary butoxy, pentoxy,isopentoxy, hexoxy, isohexoxy allyloxy, propargyloxy, and the like.

Halogen (halo) refers to chlorine, fluorine, iodine or bromine.

Aryl refers to aromatic rings e.g., phenyl, substituted phenyl and thelike, as well as rings which are fused, e.g., naphthyl, phenanthrenyland the like. An aryl group thus contains at least one ring having atleast 6 atoms, with up to five such rings being present, containing upto 22 atoms therein, with alternating (resonating) double bonds betweenadjacent carbon atoms or suitable heteroatoms. Examples of aryl groupsare phenyl, naphthyl, tetrahydronaphthyl, indanyl, biphenyl,phenanthryl, anthryl or acenaphthyl and phenanthrenyl, preferablyphenyl, naphthyl or phenanthrenyl. Aryl groups may likewise besubstituted as defined. Preferred substituted aryls include phenyl andnaphthyl.

The term heterocyclyl or heterocyclic, as used herein, represents astable 5- to 7-membered monocyclic or stable. 8- to 11-membered bicyclicheterocyclic ring which is either saturated or unsaturated, and whichconsists of carbon atoms and from one to four heteroatoms selected fromthe group consisting of N, O, and S, and including any bicyclic group inwhich any of the above-defined heterocyclic rings is fused to a benzenering. The heterocyclic ring may be attached at any heteroatom or carbonatom which results in the creation of a stable structure. A fusedheterocyclic ring system may include carbocyclic rings and need includeonly one heterocyclic ring. The term heterocycle or heterocyclicincludes heteroaryl moieties. Examples of such heterocyclic elementsinclude, but are not limited to, azepinyl, benzimidazolyl,benzisoxazolyl, benzofurazanyl, benzopyranyl, benzothiopyranyl,benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, chromanyl,cinnolinyl, dihydrobenzofuryl, dihydrobenzothienyl,dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone,dihydropyrrolyl, 1,3-dioxolanyl, furyl, imidazolidinyl, imidazolinyl,imidazolyl, indolinyl, indolyl, isochromanyl, isoindolinyl,isoquinolinyl, isothiazolidinyl, isothiazolyl, isothiazolidinyl,morpholinyl, naphthyridinyl, oxadiazolyl, 2-oxoazepinyl, oxazolyl,2-oxopiperazinyl, 2-oxopiperdinyl, 2-oxopyrrolidinyl, piperidyl,piperazinyl, pyridyl, pyrazinyl, pyrazolidinyl, pyrazolyl, pyridazinyl,pyrimidinyl, pyrrolidinyl, pyrrolyl, quinazolinyl, quinolinyl,quinoxalinyl, tetrahydrofuryl, tetrahydroisoquinolinyl,tetrahydroquinolinyl, thiamorpholinyl, thiamorpholinyl sulfoxide,thiazolyl, thiazolinyl, thienofuryl, thienothienyl, and thienyl.Preferably, heterocycle is selected from 2-azepinonyl, benzimidazolyl,2-diazapinonyl, dihydroimidazolyl, dihydropyrrolyl, imidazolyl,2-imidazolidinonyl, indolyl, isoquinolinyl, morpholinyl, piperidyl,piperazinyl, pyridyl, pyrrolidinyl, 2-piperidinonyl, 2-pyrimidinonyl,2-pyrollidinonyl, quinolinyl, tetrahydrofuryl, tetrahydroisoquinolinyl,and thienyl.

The term “heteroatom” means O, S or N, selected on an independent basis.

The term “heteroaryl” refers to a monocyclic aromatic hydrocarbon grouphaving 5 or 6 ring atoms, or a bicyclic aromatic group having 8 to 10atoms, containing at least one heteroatom, O, S or N, in which a carbonor nitrogen atom is the point of attachment, and in which one or twoadditional carbon atoms is optionally replaced by a heteroatom selectedfrom O or S, and in which from 1 to 3 additional carbon atoms areoptionally replaced by nitrogen heteroatoms, said heteroaryl group beingoptionally substituted as described herein. Examples of suchheterocyclic elements include, but are not limited to, benzimidazolyl,benzisoxazolyl, benzofurazanyl, benzopyranyl, benzothiopyranyl,benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, chromanyl,cinnolinyl, dihydrobenzofuryl, dihydrobenzothienyl,dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone, furyl,imidazolyl, indolinyl, indolyl, isochromanyl, isoindolinyl,isoquinolinyl, isothiazolyl, naphthyridinyl, oxadiazolyl, pyridyl,pyrazinyl, pyrazolyl, pyridazinyl, pyrimidinyl, pyrrolyl, quinazolinyl,quinolinyl, quinoxalinyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl,thiazolyl, thienofuryl, thienothienyl, thienyl and triazolyl. Additionalnitrogen atoms may be present together with the first nitrogen andoxygen or sulfur, giving, e.g., thiadiazole.

This invention is also concerned with a method of treating ocularhypertension or glaucoma by administering to a patient in need thereofone of the compounds of formula I in combination with a β-adrenergicblocking agent such as timolol, a parasympathomimetic agent such aspilocarpine, carbonic anhydrase inhibitor such as dorzolamide,acetazolamide, metazolamide or brinzolamide, EP4 agonist as disclosed inU.S. Ser. No. 60/386,641, filed Jun. 6, 2002 (Attorney Docket MC059PV),60/421,402, filed Oct. 25, 2002 (Attorney Docket MC067PV), 60/457,700,filed Mar. 26, 2003 (Attorney Docket MC080PV), 60/406,530, filed Aug.28, 2002 (Attorney Docket MC060PV) and PCT applications PCT 02/38039,filed Nov. 27, 2002 and PCT 02/38040, filed Nov. 27, 2002, allincorporated by reference in its entirety herein, a prostaglandin suchas latanoprost, rescula, S1033 or a prostaglandin derivative such as ahypotensive lipid derived from PGF2α prostaglandins. An example of ahypotensive lipid (the carboxylic acid group on the α-chain link of thebasic prostaglandin structure is replaced with electrochemically neutralsubstituents) is that in which the carboxylic acid group is replacedwith a C₁₋₆ alkoxy group such as OCH₃ (PGF_(2a) 1-OCH₃), or a hydroxygroup (PGF_(2a) 1-OH).

Preferred potassium channel blockers are calcium activated potassiumchannel blockers. More preferred potassium channel blockers are highconductance, calcium activated potassium (Maxi-K) channel blockers.Maxi-K channels are a family of ion channels that are prevalent inneuronal, smooth muscle and epithelial tissues and which are gated bymembrane potential and intracellular Ca²⁺.

Intraocular pressure (IOP) is controlled by aqueous humor dynamics.Aqueous humor is produced at the level of the non-pigmented ciliaryepithelium and is cleared primarily via outflow through the trabecularmeshwork. Aqueous humor inflow is controlled by ion transport processes.It is thought that maxi-K channels in non-pigmented ciliary epithelialcells indirectly control chloride secretion by two mechanisms; thesechannels maintain a hyperpolarized membrane potential (interiornegative) which provides a driving force for chloride efflux from thecell, and they also provide a counter ion (K⁺) for chloride ionmovement. Water moves passively with KCl allowing production of aqueoushumor. Inhibition of maxi-K channels in this tissue would diminishinflow. Maxi-K channels have also been shown to control thecontractility of certain smooth muscle tissues, and, in some cases,channel blockers can contract quiescent muscle, or increase the myogenicactivity of spontaneously active tissue. Contraction of ciliary musclewould open the trabecular meshwork and stimulate aqueous humor outflow,as occurs with pilocarpine. Therefore maxi-K channels could profoundlyinfluence aqueous humor dynamics in several ways; blocking this channelwould decrease IOP by affecting inflow or outflow processes or by acombination of affecting both inflow/outflow processes.

The present invention is based upon the finding that maxi-K channels, ifblocked, inhibit aqueous humor production by inhibiting net solute andH₂O efflux and therefore lower IOP. This finding suggests that maxi-Kchannel blockers are useful for treating other ophthamologicaldysfunctions such as macular edema and macular degeneration. It is knownthat lowering IOP promotes blood flow to the retina and optic nerve.Accordingly, the compounds of this invention are useful for treatingmacular edema and/or macular degeneration.

Macular edema is swelling within the retina within the criticallyimportant central visual zone at the posterior pole of the eye. Anaccumulation of fluid within the retina tends to detach the neuralelements from one another and from their local blood supply, creating adormancy of visual function in the area.

Glaucoma is characterized by progressive atrophy of the optic nerve andis frequently associated with elevated intraocular pressure (IOP). It ispossible to treat glaucoma, however, without necessarily affecting IOPby using drugs that impart a neuroprotective effect. See Arch.Ophthalmol. Vol. 112, January 1994, pp. 37-44; Investigative Ophthamol.& Visual Science, 32, 5, April 1991, pp. 1593-99. It is believed thatmaxi-K channel blockers which lower IOP are useful for providing aneuroprotective effect. They are also believed to be effective forincreasing retinal and optic nerve head blood velocity and increasingretinal and optic nerve oxygen by lowering IOP, which when coupledtogether benefits optic nerve health. As a result, this inventionfurther relates to a method for increasing retinal and optic nerve headblood velocity, increasing retinal and optic nerve oxygen tension aswell as providing a neuroprotective effect or a combination thereof.

As indicated above, potassium channel antagonists are useful for anumber of physiological disorders in mammals, including humans. Ionchannels, including potassium channels, are found in all mammalian cellsand are involved in the modulation of various physiological processesand normal cellular homeostasis. Potassium ions generally control theresting membrane potential, and the efflux of potassium ions causesrepolarization of the plasma membrane after cell depolarization.Potassium channel antagonists prevent repolarization and enable the cellto stay in the depolarized, excited state.

There are a number of different potassium channel subtypes.Physiologically, one of the most important potassium channel subtypes isthe Maxi-K channel which is present in neuronal tissue, smooth muscleand epithelial tissue. Intracellular calcium concentration (Ca²⁺ _(i))and membrane potential gate these channels. For example, Maxi-K channelsare opened to enable efflux of potassium ions by an increase in theintracellular Ca²⁺ concentration or by membrane depolarization (changein potential). Elevation of intracellular calcium concentration isrequired for neurotransmitter release. Modulation of Maxi-K channelactivity therefore affects transmitter release from the nerve terminalby controlling membrane potential, which in turn affects the influx ofextracellular Ca²⁺ through voltage-gated calcium channels. The compoundsof the present invention are therefore useful in the treatment ofneurological disorders in which neurotransmitter release is impaired.

A number of marketed drugs function as potassium channel antagonists.The most important of these include the compounds Glyburide, Glipizideand Tolbutamide. These potassium channel antagonists are useful asantidiabetic agents. The compounds of this invention may be combinedwith one or more of these compounds to treat diabetes.

Potassium channel antagonists are also utilized as Class 3antiarrhythmic agents and to treat acute infarctions in humans. A numberof naturally occuring toxins are known to block potassium channelsincluding Apamin, Iberiotoxin, Charybdotoxin, Noxiustoxin, Kaliotoxin,Dendrotoxin(s), mast cell degranuating (MCD) peptide, and β-Bungarotoxin(β-BTX). The compounds of this invention may be combined with one ormore of these compounds to treat arrhythmias.

Depression is related to a decrease in neurotransmitter release. Currenttreatments of depression include blockers of neurotransmitter uptake,and inhibitors of enzymes involved in neurotransmitter degradation whichact to prolong the lifetime of neurotransmitters.

Alzheimer's disease is also characterized by a diminishedneurotransmitter release. Alzheimer's disease is a neurodegenerativedisease of the brain leading to severely impaired cognition andfunctionality. This disease leads to progressive regression of memoryand learned functions. Alzheimer's disease is a complex disease thataffects cholinergic neurons, as well as serotonergic, noradrenergic andother central neurotransmitter systems. Manifestations of Alzheimer'sdisease extend beyond memory loss and include personality changes,neuromuscular changes, seizures, and occasionally psychotic features.

Alzheimer's disease is the most common type of dementia in the UnitedStates. Some estimates suggest that up to 47% of those older than 85years have Alzheimer's disease. Since the average age of the populationis on the increase, the frequency of Alzheimer's disease is increasingand requires urgent attention. Alzheimer's is a difficult medicalproblem because there are presently no adequate methods available forits prevention or treatment.

Three classes of drugs are being investigated for the treatment ofAlzheimer's disease. The first class consists of compounds that augmentacetylcholine neurotransmitter function. Currently, cholinergicpotentiators such as the anticholinesterase drugs are being used in thetreatment of Alzheimer's disease. In particular, physostigmine(eserine), an inhibitor of acetylcholinesterase, has been used in itstreatment. The administration of physostigmine has the drawback of beingconsiderably limited by its short half-life of effect, poor oralbioavailability, and severe dose-limiting side-effects, particularlytowards the digestive system. Tacrine (tetrahydroaminocridine) isanother cholinesterase inhibitor that has been employed; however, thiscompound may cause hepatotoxicity.

A second class of drugs that are being investigated for the treatment ofAlzheimer's disease is nootropics that affect neuron metabolism withlittle effect elsewhere. These drugs improve nerve cell function byincreasing neuron metabolic activity. Piracetam is a nootropic that maybe useful in combination with acetylcholine precursors and may benefitAlzheimer's patients who retain some quantity of functionalacetylcholine release in neurons. Oxiracetam is another related drugthat has been investigated for Alzheimer treatment.

A third class of drugs is those drugs that affect brain vasculature. Amixture of ergoloid mesylates is used for the treatment of dementia.Ergoloid mesylates decrease vascular resistance and thereby increasecerebral blood flow. Also employed are calcium channel blocking drugsincluding Nimodipine which is a selective calcium channel blocker thataffects primarily brain vasculature.

Other miscellaneous drugs are targeted to modify other defects found inAlzheimer's disease. Selegiline, a monoamine oxidase B inhibitor, whichincreases brain dopamine and norepinephrine has reportedly caused mildimprovement in some Alzheimer's patients. Aluminum chelating agents havebeen of interest to those who believe Alzheimer's disease is due toaluminum toxicity. Drugs that affect behavior, including neuroleptics,and anxiolytics have been employed. Side effects of neuroleptics rangefrom drowsiness and anti cholinergic effects to extrapyramidal sideeffects; other side effects of these drugs include seizures,inappropriate secretion of antidiuretic hormone, jaundice, weight gainand increased confusion. Anxiolytics, which are mild tranquilizers, areless effective than neuroleptics, but also have milder side effects. Useof these behavior-affecting drugs, however, remains controversial. Thepresent invention is related to novel compounds which are useful aspotassium channel antagonists. It is believed that certain diseases suchas depression, memory disorders and Alzheimers disease are the result ofan impairment in neurotransmitter release. The potassium channelantagonists of the present invention may therefore be utilized as cellexcitants which should stimulate an unspecific release ofneurotransmitters such as acetylcholine, serotonin and dopamine.Enhanced neurotransmitter release should reverse the symptoms associatedwith depression and Alzheimers disease.

The compounds within the scope of the present invention exhibitpotassium channel antagonist activity and thus are useful in disordersassociated with potassium channel malfunction. A number of cognitivedisorders such as Alzheimer's Disease, memory loss or depression maybenefit from enhanced release of neurotransmitters such as serotonin,dopamine or acetylcholine and the like. Blockage of Maxi-K channelsmaintains cellular depolarization and therefore enhances secretion ofthese vital neurotransmitters.

The compounds of this invention may be combined with anticholinesterasedrugs such as physostigmine (eserine) and Tacrine(tetrahydroaminocridine), nootropics such as Piracetam, Oxiracetam,ergoloid mesylates, selective calcium channel blockers such asNimodipine, or monoamine oxidase B inhibitors such as Selegiline, in thetreatment of Alzheimer's disease. The compounds of this invention mayalso be combined with Apamin, Iberiotoxin, Charybdotoxin, Noxiustoxin,Kaliotoxin, Dendrotoxin(s), mast cell degranuating (MCD) peptide,β-Bungarotoxin (β-BTX) or a combination thereof in treating arrythmias.The compounds of this invention may further be combined with Glyburide,Glipizide, Tolbutamide or a combination thereof to treat diabetes.

The herein examples illustrate but do not limit the claimed invention.Each of the claimed compounds are potassium channel antagonists and arethus useful in the decribed neurological disorders in which it isdesirable to maintain the cell in a depolarized state to achieve maximalneurotransmitter release. The compounds produced in the presentinvention are readily combined with suitable and known pharmaceuticallyacceptable excipients to produce compositions which may be administeredto mammals, including humans, to achieve effective potassium channelblockage.

For use in medicine, the salts of the compounds of formula I will bepharmaceutically acceptable salts. Other salts may, however, be usefulin the preparation of the compounds according to the invention or oftheir pharmaceutically acceptable salts. When the compound of thepresent invention is acidic, suitable “pharmaceutically acceptablesalts” refers to salts prepared form pharmaceutically acceptablenon-toxic bases including inorganic bases and organic bases. Saltsderived, from inorganic bases include aluminum, ammonium, calcium,copper, ferric, ferrous, lithium, magnesium, manganic salts, manganous,potassium, sodium, zinc and the like. Particularly preferred are theammonium, calcium, magnesium, potassium and sodium salts. Salts derivedfrom pharmaceutically acceptable organic non-toxic bases include saltsof primary, secondary and tertiary amines, substituted amines includingnaturally occurring substituted amines, cyclic amines and basic ionexchange resins, such as arginine, betaine caffeine, choline,N,N¹-dibenzylethylenediamine, diethylamin, 2-diethylaminoethanol,2-dimethylaminoethanol, ethanolamine, ethylenediamine,N-ethylmorpholine, N-ethylpiperidine, glucamine, glucosamine, histidine,hydrabamine, isopropylamine, lysine, methylglucamine, morpholine,piperazine, piperidine, polyamine resins, procaine, purines,theobromine, triethylamine, trimethylamine tripropylamine, tromethamineand the like.

When the compound of the present invention is basic, salts may beprepared from pharmaceutically acceptable non-toxic acids, includinginorganic and organic acids. Such acids include acetic, benzenesulfonic,benzoic, camphorsulfonic, citric, ethanesulfonic, fumaric, gluconic,glutamic, hydrobromic, hydrochloric, isethionic, lactic, maleic, malic,mandelic, methanesulfonic, mucic, nitric, pamoic, pantothenic,phosphoric, succinic, sulfuric, tartaric, p-toluenesulfonic acid and thelike. Particularly preferred are citric, hydrobromic, hydrochloric,maleic, phosphoric, sulfuric and tartaric acids.

The preparation of the pharmaceutically acceptable salts described aboveand other typical pharmaceutically acceptable salts is more fullydescribed by Berg et al., “Pharmaceutical Salts,” J. Pharm. Sci.,1977:66:1-19.

As used herein, the term “composition” is intended to encompass aproduct comprising the specified ingredients in the specific amounts, aswell as any product which results, directly or indirectly, fromcombination of the specific ingredients in the specified amounts.

When a compound according to this invention is administered into a humansubject, the daily dosage will normally be determined by the prescribingphysician with the dosage generally varying according to the age,weight, sex and response of the individual patient, as well as theseverity of the patient's symptoms.

The maxi-K channel blockers used can be administered in atherapeutically effective amount intravaneously, subcutaneously,topically, transdermally, parenterally or any other method known tothose skilled in the art. Ophthalmic pharmaceutical compositions arepreferably adapted for topical administration to the eye in the form ofsolutions, suspensions, ointments, creams or as a solid insert.Ophthalmic formulations of this compound may contain from 0.01 to 5% andespecially 0.5 to 2% of medicament. Higher dosages as, for example,about 10% or lower dosages can be employed provided the dose iseffective in reducing intraocular pressure, treating glaucoma,increasing blood flow velocity or oxygen tension. For a single dose,from between 0.001 to 5.0 mg, preferably 0.005 to 2.0 mg, and especially0.005 to 1.0 mg of the compound can be applied to the human eye.

The pharmaceutical preparation which contains the compound may beconveniently admixed with a non-toxic pharmaceutical organic carrier, orwith a non-toxic pharmaceutical inorganic carrier. Typical ofpharmaceutically acceptable carriers are, for example, water, mixturesof water and water-miscible solvents such as lower alkanols oraralkanols, vegetable oils, polyalkylene glycols, petroleum based jelly,ethyl cellulose, ethyl oleate, carboxymethylcellulose,polyvinylpyrrolidone, isopropyl myristate and other conventionallyemployed acceptable carriers. The pharmaceutical preparation may alsocontain non-toxic auxiliary substances such as emulsifying, preserving,wetting agents, bodying agents and the like, as for example,polyethylene glycols 200, 300, 400 and 600, carbowaxes 1,000, 1,500,4,000, 6,000 and 10,000, antibacterial components such as quaternaryammonium compounds, phenylmercuric salts known to have cold sterilizingproperties and which are non-injurious in use, thimerosal, methyl andpropyl paraben, benzyl alcohol, phenyl ethanol, buffering ingredientssuch as sodium borate, sodium acetates, gluconate buffers, and otherconventional ingredients such as sorbitan monolaurate, triethanolamine,oleate, polyoxyethylene sorbitan monopalmitylate, dioctyl sodiumsulfosuccinate, monothioglycerol, thiosorbitol, ethylenediaminetetracetic acid, and the like. Additionally, suitable ophthalmicvehicles can be used as carrier media for the present purpose includingconventional phosphate buffer vehicle systems, isotonic boric acidvehicles, isotonic sodium chloride vehicles, isotonic sodium boratevehicles and the like. The pharmaceutical preparation may also be in theform of a microparticle formulation. The pharmaceutical preparation mayalso be in the form of a solid insert. For example, one may use a solidwater soluble polymer as the carrier for the medicament. The polymerused to form the insert may be any water soluble. non-toxic polymer, forexample, cellulose derivatives such as methylcellulose, sodiumcarboxymethyl cellulose, (hydroxyloweralkyl cellulose), hydroxyethylcellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose;acrylates such as polyacrylic acid salts, ethylacrylates,polyactylamides; natural products such as gelatin, alginates, pectins,tragacanth, karaya, chondrus, agar, acacia; the starch derivatives suchas starch acetate, hydroxymethyl starch ethers, hydroxypropyl starch, aswell as other synthetic derivatives such as polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether, polyethylene oxide, neutralizedcarbopol and xanthan gum, gellan gum, and mixtures of said polymer.

Suitable subjects for the administration of the formulation of thepresent invention include primates, man and other animals, particularlyman and domesticated animals such as cats and dogs.

The pharmaceutical preparation may contain non-toxic auxiliarysubstances such as antibacterial components which are non-injurious inuse, for example, thimerosal, benzalkonium chloride, methyl and propylparaben, benzyldodecinium bromide, benzyl alcohol, or phenylethanol;buffering ingredients such as sodium chloride, sodium borate, sodiumacetate, sodium citrate, or gluconate buffers; and other conventionalingredients such as sorbitan monolaurate, triethanolamine,polyoxyethylene sorbitan monopalmitylate, ethylenediamine tetraaceticacid, and the like.

The ophthalmic solution or suspension may be administered as often asnecessary to maintain an acceptable IOP level in the eye. It iscontemplated that administration to the mamalian eye will be about onceor twice daily.

For topical ocular administration the novel formulations of thisinvention may take the form of solutions, gels, ointments, suspensionsor solid inserts, formulated so that a unit dosage comprises atherapeutically effective amount of the active component or somemultiple thereof in the case of a combination therapy.

The following examples given by way of illustration is demonstrative ofthe present invention.

PREPARATIVE EXAMPLE 1 Synthesis of 6-OMe-Indole

Step A

Adapted from ref: Magnus et al., J. Am. Chem. Soc. 110, 7, 2243, 1988.

4-Methoxy-2-nitro-aniline (35 g-Aldrich) was suspended in 250 mL ofethanol followed by addition of 14 mL of concentrated sulfuric acid. Thesuspension was cooled to 0° C., followed by slow addition of isoamylnitrite (34 mL). After complete addition of isoamyl nitrite, thereaction mixture was stirred at 0 C for 1.5 h at which point a thickwhite slurry resulted. The reaction mixture was filtered and theprecipitate was washed with 200 mL of cold ethanol followed by washingwith 500 mL of ether. The filter cake was sucked dry under reducedpressure. 52 g of a free flowing powder was collected and used in thenext step directly.

Step B

A 1 L flask was charged with isopeopenyl acetate (75 mL), acetone (400mL), 0.25 M HCl (250 mL), Cu (II)Cl₂ (4 g) and LiCl (15 g). This wascooled to 0 C followed by portionwise addition of the diazonium saltobtained above. The reaction mixture was vented throughout the 18 hreaction time. The reaction mixture was concentrated to a viscous oil,diluted with ethyl acetate (200 mL) and washed with water (50 mL). Theorganic phase was collected, dried and concentrated to an orange-reddishoil which subjected to purification by SGC to provide colorless lowmelting product (16 g) LCMS=[M+H] 209

Step C

Compound obtained in step B was taken up in 200 mL of ethyl acetatefollowed by addition of 20 g of Raney Nickel (previously washed withethyl acetate). The reaction mixture was subjected to reduction withhydrogen at atmospheric pressure for 12 h. After TLC analysis indicatedcomplete conversion, the reaction mixture was filtered over a pad ofcelite and this was washed thoroughly with ethyl acetate and methanol.The combined organic extracts were concentrated to provide crystallinewhite product (12 g). LCMS: [M+H] 162. 1H NMR (CDCL, 500 MHz)): 7.8 (bs,1H); 7.4 (d, 1H, J=XHz); 6.3-6.1 (m, 3H); 3.85 (s, 3H); 2.4 (s, 3H).

The compounds of this invention can be made, with modification whereappropriate, in accordance with Schemes A and/or B. Examples 1-8 arealso produced in accordance with Schemes A and/or B.

Step A1

6-methoxy indole (1 g, 6.2 mmole —Biochemica & Synthetica (Switzerland))was charged into a 100 mL flask. After evacuation and purging withargon, 15 mL of dichloromethane was added followed by addition ofEtAlCl₂ (9.92 mmoles, 5.5 mL of a 1.8M solution in toluene), thereaction mixture was allowed to stir for 15 min after which methylmagnesium chloride (6.2 mmole, 2mL of a 3M solution in ether) was added.This was allowed to stir for another 15 min when the reaction appearedcloudy. The requisite acid chloride (6.5 mmole) was added slowly and thereaction mixture was allowed to stir for an additional 0.5 h. Thereaction mixture was diluted with 100 mL of ethyl acetate and quenchedby addition of 20 mL of a saturated solution of ammonium chloride. Theorganic phases were separated and aqueous phase was back extracted with50 mL portions of ethyl acetate twice. Combined organic extracts weredried over sodium sulphate and concentrated. The residue; which wasusually colored was triturated with 20% ether in hexanes, filtered anddried to yield acylated product in all cases. This material was used inthe Step B directly.

Step A2

4.8 mmoles of material obtained above was dissolved in 5 mL of dryDMF(dimethylformamide) followed by addition of 1 equiv. of NaH (sodiumhydride). After evolution of all hydrogen gases had ceased, whichusually took about 20 min, methyl bromo acetate (1.5 equiv.) was addedportionwise. The reaction mixture was allowed to stir for another 1 hafter which TLC (thin layer chromatography) analysis indicated completeconsumption of all starting material. The reaction mixture was dilutedwith 50 mL of ethyl acetate and washed with brine (15 mL×2). The organicphase was dried over sodium sulphate and concentrated to yield an oilwhich was applied to a SG (silica gel) column and eluted with 20% ethlyacetate in hexanes to yield alkylated product in all cases.

Step A3

Saponification of material obtained above was carried out using aqueouslithium hydroxide. 2.88 mmoles of ester was dissolved in 30 mL of THF(teterahydrofuran) and 2 quiv of LiOH (lithium hydroxide) was added as a1M solution in water. The reaction mixture was stirred vigorously for 1h. TLC analysis indicated complete reaction. The reaction mixture wasthen evaporated to half its original volume and diluted with 50 mL ofethyl acetate. 1M HCl solution was then added to bring the pH of theaqueous phase up to 2. The organic phase was separated and the aqueousphase was back extracted with 15 mL of ethyl acetate twice. Combinedorganic phases were dried over sodium sulphate and concentrated to asolid. This was azeotroped thoroughly by repeated evaporations withtoluene in order to obtain a dry solid (about 2.7 mmoles in all cases),which was ready to be used for amide formation reactions.

Step A4

Amide formation was achieved using the peptide coupling reagent PyBOP([bromo-tris-pyrrolidino-phosphonium hexafluorophosphate]-Novabiochem)as follows. Typically 0.3 mmole of starting acid was charged into a 100mL flask, followed by the addition of PyBoP (0.6 mmoles) and therequisite amino thiazole (1.2 equiv., 0.36 mmole) under argon. Thesolvent acetonitrile (2 mL) was added followed by the addition of Hunigsbase (0.9 mmoles). The reaction was sealed and heated to 100° C. forabout 1 h at which time TLC analysis indicated complete reaction. Thereaction mixture was evaporated and re-dissolved in 15 mL of ethylacetate. This was passed through a small plug of silica gel and washeddown with an additional 20 mL of ethyl acetate. The combinedorganic-phase was washed with brine, separated, dried over sodiumsulphate and concentrated. The residue was purified by normal phase orreverse phase column chromatography.

Step B1

1 g of 6-methoxy indole (Biochemica & Synthetica (Switzerland)) wasdissolved in 10 mL of DMF (dimethylformamide) followed by the additionof 1.5 equiv of NaH (9.3 mmoles, 372 mg of a 60% solution in mineraloil). The reaction mixture was allowed to stir for 1 h at rt followed bythe addition of 2 equiv of methyl bromo acetate or t-butyl bromoacetate. After 1 h the reaction was complete by TLC and it was subjectedto standard aqueous work up. Purification of crude by SGC (silica gelchromatography) provided about 4.0-4.5 mmoles of product.

Step B2

4.0 mmoles of product obtained above was dissolved in 15 mL ofdichloromethane under argon. The reaction mixture was cooled to 0° C.followed by the addition of 1.2 equiv of ethyl aluminum dichloride.After 1 h at 0° C. the requisite acid chloride (1.2 equiv) was added andthe reaction mixture was stirred for an additional 1 h at 0° C. TLC(thin layer chromatography) analysis at this stage indicated completereaction and the reaction was subjected to a standard aqueous work up.SGC (silica gel chromatography) purification provided about 3.5 mmolesof product.

Step B3a (hydrolysis of methyl ester)

The methyl ester obtained above (3.5 mmoles) was dissolved in 25 mL ofTHF (tetrahydrofuran) followed by the addition of 1.5 equiv of a 1Msolution of LiOH in water. The reaction was stirred for 0.5 h at whichtime TLC analysis indicated complete hydrolysis. The reaction mixturewas diluted with 15 mL of ethyl acetate and acidified with 2 mL of 1MHCl. The organic extracts were separated, dried over sodium sulfate andconcentrated. The residue was suspended in toluene and evaporated twiceto give the acid as white solid (3.3 mmoles) which was used in the nextstep directly.

Step B3b(hydrolysis of t-butyl ester)

The t-butyl ester obtained above (3.5 mmoles) was dissolved in 10 mL ofdichloromethane followed by the addition of 5 mL of TFA(trifluoroaceticacid). The reaction was allowed to stir at rt for 1 h atwhich point TLC analysis indicated complete reaction. The solvent wasstripped and resulting residue was resuspended in toluene and evaporatedto dryness twice to the acid as a white solid (3.3 mmoles) which wasused in the next step directly.

Step B4

Amide formation was achieved using the peptide coupling reagent PyBoP(Novabiochem) as follows. Typically 0.3 mmole of starting acid wascharged into a 100 mL flask, followed by the addition of PyBoP (0.6mmoles) and the requisite amino thiazole (1.2 equiv., 0.36 mmole) underargon. The solvent acetonitrile (2 mL) was added followed by theaddition of Hunigs base (0.9 mmoles). The reaction was sealed and heatedto 100° C. for about 1 h at which time TLC analysis indicated completereaction. The reaction mixture was evaporated and redissolved in 15 mLof ethyl acetate. This was passed through a small plug of silica gel andwashed down with an additional 20 mL of ethyl acetate. The combinedorganic phase was washed with brine, separated, dried over sodiumsulphate and concentrated. The residue was purified by normal phase orreverse phase column chromatography.

EXAMPLE 1

1H NMR (CDCl₃): 8.35 (1H, d, J=9 Hz); 7.85 (2H, bd, J=7.5 Hz); 7.6-7.48(6H, m); 7.02 ( 1H, dd, J=9 Hz & 2 Hz); 5.2 (2H, bs); 4.4 (2H, bm); 3.9(3H, s); 1.5 (3H, m). LCMS: [M+H]=420.

EXAMPLE 2

1H NMR (CDCl₃): 8.35 (1H, d, J=9 Hz); 7.85 (2H, bd, J=7.5 Hz); 7.6-7.48(6H, m); 7.02 (1H, dd, J=9 Hz & 2 Hz); 5.2 (2H, bs); 4.4 (2H, bm); 3.9(3H, s); 1.5 (3H, m). LCMS: [M+H]=420.

EXAMPLE 3

1H NMR (CDCl₃): 7.90 (1H, d, J=9 Hz); 7.60 (1H, d, J=3.5 H-z); 7.1 (1H,bs); 6.93 (1H, dd, J=9Hz & 2 Hz); 6.67 (1H, d, J=2 Hz); 5.2 (2H, bs);4.4 (2H, bm); 3.9 (3H, s); 3.1 (2H, q); 1.5 (3H, m); 1.3 (3H, t). LCMS:[M+H]=372.

EXAMPLE 4

1H NMR (CDCl₃): 7.80(1H, d, J=9Hz); 7.41 (1H, d, J=4 Hz); 7.03 (1H, d,J=4 Hz); 6.84 (1H, dd, J=9 Hz & 2 Hz); 6.75 (1H, d, J=2 Hz); 5.1 (2H,s); 3.8 (3H, s); 3.0 (2H, q); 1.3 (3H, t). LCMS: [M+H]=344.

EXAMPLE 5

1H NMR (CDCl₃): 8.98 (2H, d, J=4.5 Hz); 7.63 (1H, d, J=3.5 Hz); 7.51(2H, dd, J=5 Hz); ); 7.21 (1H, bs); 7.15 (1H, d, J=9 Hz); 6.79 (1H, dd,J=9 Hz & 2 Hz); 6.65 (1H, d, J=2 Hz); 5.2 (2H, bs); 4.4 (2H, bm); 3.9(3H, s); 2.45 (3H, bs); 1.5 (3H, m). LCMS: [M+H]=436.

EXAMPLE 6

1H NMR (CDCl₃): 7.65 (1H, d, J=9 Hz); 7.63 (1H, d, J=3.5 Hz); 7.45 (1H,bs); 7.27 ( 1H, bs); 7.15 (1H, bs); 6.84 (1H, m); 6.62 (1H, bs); 5.2(2H, bs); 4.4 (2H, bm); 3.9 (3H, s); 3.8 (3H, s); 2.45 (3H, bs); 1.5(3H, m). LCMS: [M+H]=438.

EXAMPLE 7

1H NMR (CDCl₃): 8.79 (1H, d, J=9 Hz); 7.85 (2H, bd, J=7.5 Hz); 7.6-7.48(6H, m); 7.02 (1H, dd, J=9 Hz & 2 Hz); 5.2 (2H, bs); 4.4 (2H, bm); 3.9(3H,s); 1.5 (3H, m). LCMS: M+H]=420.

EXAMPLE 8

Mass spectrum (ESI) 492 (M+1). 1H NMR (500 MHz, DMSO-d₆): δ1.42 (t, 3H,J=6.8 Hz); 2.56(t, 2H, J=7.5 Hz); 2.90(t, 2H, J=7.5 Hz); 3.78(s, 3H);4.32(m, 2H); 5.63(s, 2H); 6.91(dd, 1H, J=8.5, 2.0 Hz); 7.17(d, 1H, J=1.5Hz); 7.28(d, 1H, J=3.0 Hz); 7.39(d, 2H, J=8.0 Hz); 7.56(d, 1H, J=3.5Hz); 7.69(d, 2H, J=8.0 Hz); 8.01(s, 1H); 8.14(d, 1H, J=8.5 Hz).

EXAMPLE 9

1H NMR (CDCl₃): 7.77 (2H, d); 7.58 (1H, bs); 7.45 (2H, d); 7.25 (1H,d,); 7.10 (1H, bd), 6.77 (1H, dd); 6.67 (1H, d); 5.30 (2H, bs); 4.48(2H, bm); 3.84 (3H, s); 2.70 (2H, bm); 2.50 (3H, s); 2.28 (2H, bm); 2.21(3H, bs).

The compounds illustrated in Examples 10-12 were prepared as shown inSchemes A and B above but substituting the appropriately substitutedamine in either Step A4 or B4 for the substituted amino thiazole shownin the schemes.

EXAMPLE 10

1H NMR (CDCl₃): 7.72 (2H, d); 7.42 (2H, d); 7.39 (1H, dd); 7.20 (1H,d,); 7.08 (1H, dd), 7.04 (1H, dd); 6.74 (1H, dd); 6.62 (1H, d); 4.72(2H, s); 3.87 (3H, s); 3.84 (2H, q); 2.45 (3H, s); 1.22 (3H, t). LCMS(M+H)=467.

EXAMPLE 11

1H NMR (DMSO): 7.88(1H, d); 7.64 (2H, d); 7.59 (2H, d,); 7.32 (1H, d),7.10 (4H, m); 6.74 (1H, dd); 5.58 (1H, d); 5.24 (1H, d); 4.90 (1H, m);3.76 (3H, s); 3.50 (1H, m); 2.78 (1H, d); 2.49 (3H, s); 1.40 (3H, d).LCMS (M+H)=473.

EXAMPLE 12

1H NMR (CDCl₃): 7.76 (2H, d); 7.44 (2H, d); 7.19 (1H, d); 6.75 (1H, dd);6.65 (1H, d); 4.86 (2H, s); 3.85 (3H, s); 3.55 (2H, q); 2.51 (3H, s);1.50 (9H, s); 1.43 (9H, s). LCMS (M+H)=441.

EXAMPLE 13

1H NMR (DMSO): 8.10 (1H, d); 7.94 (1H, s); 7.76 (2H, d); 7.60 (2H, d,);7.14 (1H, d), 6.93 (1H, dd); 5.20 (2H, s); 4.17 (2H, q); 3.80 (3H, s);1.22 (3H, t). LCMS ((M+H)=372.

EXAMPLE 14

1H NMR (CDCl₃): 7.73 (2H, d); 7.44 (2H, d); 7.20 (1H, d); 6.74 (1H, d);6.51 (1H, s); 5.01 (2H, s); 3.82 (3H, s); 2.37 (3H, s); 1.37 (9H, s).LCMS (M+H)=398.

Step 1 Allyl amino-imidazoline

2-Methyl thio-2-imidazoline hydroiodide (1 mmole) was mixed with allylamine (2 mmole) in 10 mL of dichloromethane at room temperature. Thereaction was stirred for 12 h at which point TLC analysis indicatedcompletion of reaction. Reaction mixture was concentrated and theresidual oil was applied to SGC and eluted with 1-5% methanol indichloromethane. 0.9 mmole of desired product was obtained as an oil.

1H NMR (DMSO-d₆): 8.39 (1H, bm); 5.8 (1H, m); 5.2 (2H, m); 3.8 (2H, bm);3.6 (4H, bs);

Step 2

Compound C-1 (1 g, 1.83 mmoles, prepared as shown in Scheme A) wascharged into a 100 mL flask followed by the addition of Pd(OAc)₂ (10 mol%). 15 mL of acetonirile was added followed by the addition of triethylamine (2.5 equiv.) and allyl aminoimidazoline (1.2 equiv., 2.2 mmoles)¹.The reaction mixture was purged with argon, sealed and heated at 80° C.for 7 h at which time TLC analysis indicated the completion of reaction.The reaction mixture was filtered and concentrated to 20% originalvolume. This was loaded onto a reverse phase HPLC column and purified toprovide instant compound C-2. Product obtained was used in thehydrogenation step. LCMS [M+H]=543

Step 3

The product obtained above was dissolved in methanol (10 mL) followed byaddition of Pd—C (10%) and the reaction was evacuated and back purgedwith hydrogen using a balloon. TLC analysis indicated that reaction wascomplete after 1 h. The reaction mixture was filtered over a pad ofcelite. Concentration and purification reverse phase HPLC provideddesired Compound C-2 as a white solid.

1HNMR: (DMSO-d₆): δ 8.10 (1H, d, J=8.5 Hz); 7.77 (3H, m); 7.53 (1H, bs);7.37 (2H, d, J=8 Hz); 6.97 (1H, m); 6.94 (1H, m); 5.51 (2H, bs); 4.36(1H, bs); 83.82 (3H, s); 3.69 (4H, bs); 3.2 (2H, m); 2.8 (2H, m); 1.9(2H, m); 1.45 (2H, bs); LCMS [M+H]=545.

ProcedureStep 1

Compound D-2 was obtained as described in general scheme A above.

Step 2

Compound D-4 was synthesized as follows: 1.8 g of compound D-2 wasdissolved in 6 mL of DMF followed by addition of sodium hydride (1.2equiv.). The reaction was allowed to stir for 0.5 h at room temperaturethen methyl-3-bromopropionate was added (1.5 equiv.). The reaction wasallowed to stir for 0.5 h at which point TLC analysis indicated completeconsumption of starting material. The reaction was poured into 50 mL ofwater, stirred for 0.5 h at which time the resultant solids formed werecollected by filtration and dried thoroughly. The resulting solids weredissolved in 30 mL of THF followed by the addition of a solution of 1MLiOH in water. The reaction was stirred for 1 h at which point TLCanalysis indicated completion of reaction. The solvents were evaporatedand upon acidification the resulting solids were collected and driedthoroughly before use in te next step.

Step 3

100 mg of acid D-4 obtained in the Step 2 was charged into a 100 mLflask followed by the addition of pyBop (2 equiv.) and cyclohexyl aminothiazole (1.2 equiv) and Hunigs base (3.5 equiv.). The solvent used wasacetonitrile (10 mL). The reaction was heated in an inert atmosphere for1 h. standard aqueous and purification provided 19% yield of desiredcompound D-5 [M+H]=522.

Compound D-6

Using a similar procedure (as described for the preparation of compoundD-5) on a 100 mg scale, acid D-4 was coupled with cyclopropyl methylamino thiazole to provide compound D-6. [M+H]=494.

Compound D-7

100 mg of acid D-4 was treated with 1.5 equiv. of dicylohexylcarbodiimide in 10 mL of dichloromethane. The reaction mixture washeated to reflux for 1 h after which the reaction was concentrated ndpurified using silica gel chromatography to provide 69% of desiredcompound G [M+H]=564.

EXAMPLE 15

A suspension of chloroacetone (6.00 grams, 65 mmol, filtered throughbasic alumina prior to use), phenol 1 (10.00 grams, 65 mmol) andpotassium carbonate (8.96 grams, 65 mmol) was stirred in DMF at roomtemperature under nitrogen atmosphere for 1 hour. The was then dilutedwith ethyl acetate/H₂O and the layers separated. The aqueous layer wasacidified with 1N HCl and extracted with ethyl acetate (3×). The organiclayer was then washed with water (2×), and brine (1×), dried with sodiumsulfate, filtered and evaporated to give intermediate a;

¹H-NMR (CDCl₃ 500 MHz) δ 8.14 (t, 1H), 7.53 (t, 1H), 7.35 (d, 1H), 7.27(d, 1H), 3.78 (s, 2H), 2.35 (s, 3H).

Intermediate a (1.84 grams, 8.75 mmol) and 4-trifluoromethoxyphenylhydrazine hydrochloride (2.00 grams, 4.76mmol) were stirred at100° C. in acetic acid (40 mL, 0.22M) for 1 hour under nitrogenatmosphere to give a 1:2 mixture of 4- and 6-trifluoromethoxy indoles.The reaction was cooled to room temperature, the acetic acid was removedunder reduced pressure and the residue was diluted with ethyl acetateand washed with water (1×) and brine (1×). The organic layer was driedwith sodium sulfate, filtered and evaporated to afford intermediatecompound b as a yellow oil after chromatography (hexanes/ethylacetate/1% acetic acid, 6:1) ¹H-NMR (CDCl₃ 500 MHz) δ 8.43 (br s, 1H),8.16 (dd, 1H), 7.46 (d, 1H), 7.23 (t, 1H), 7.14 (t, 1H), 7.03 (d, 1H),6.74 (d, 1H), 2.54 (s, 3H).

A solution of ntermediate b (0.29 grams, 0.78 mmol) and thiosalicylicacid (0.12 grams, 0.78 mmol) in trifluoroacetic acid (3 mL, 0.26M) washeated to 50° C. under nitrogen atmosphere for 2 hours. After this timethe reaction was cooled to room temperature, diluted with ethyl acetateand washed with 1N NaOH (2×), and brine (1×). The organic layer wasdried with sodium sulfate, filtered and evaporated to afford compound c;

1H-NMR (CDCl₃ 500 MHz) δ 8.01 (br s, 1H), 7.49 (d, 1H), 7.17 (s, 1H),6.99 (d, 1H), 6.26 (s, 1H), 2.46 (s, 3H).

Zinc Chloride (0.23 grams, 1.66 mmol) and ethyl magnesium bromide (0.29mL of a 3M solution in ether, 0.87 mmol) were added to a solution ofcompound c (0.16 grams, 0.74 mmol) in CH2Cl2. The resulting mixture wasstirred at room temperature under a nitrogen atmosphere for 1 hour.4-chlorobenzoyl chloride (0.21 grams, 1.18 mmol) was then added andstirring was continued for 1 hour. Aluminum chloride (0.053 grams 0.39mmol) was added and the reaction mixture was stirred for 3 hours. Thereaction was then quenched with NH4Cl(aq), diluted with CH2Cl2, washedwith 1N NaOH (1×) and brine (3×). The organic layer was dried withsodium sulfate, filtered and evaporated to afford compound d afterchromatography (hexanes/ethyl acetate, 4:1); ¹H-NMR (CDCl₃ 500 MHz) δ8.54 (br s, 1H), 7.73 (d, 2H), 7.48 (d, 2H), 7.40 (d, 1H), 7.24 (s, 1H),7.02 (d, 1H), 2.60 (s, 3H).

A solution of compound d (101 milligrams, 0.286 mmol), methylbromoacetate (51 milligrams, 0.342 mmol) and Cs2CO3 (121 milligrams,0.342 mmol) was stirred in DMF (1.4 mL) at toom temperature for 18hours. The reaction was diluted with ether then washed with water (3×),brine(1×), dried, filtered, and evaporated to afford a light yellowsolid that was saponified without purification. The ester was stirredwith NaOH (0.340 mL, 1.0 M aq.) in THF/MeOH (3:1) for 18 hours. Thereaction was diluted with ether and acidified with 1N HCl to pH 3. Theorganic layer was separated and washed with water (2×), brine (1×) thendried filtered and evaporated to give compound e;

¹H-NMR (CDCl₃ 500 MHz) δ 7.74 (d, 8.6 Hz, 2H), 7.45 (d, 8.6 Hz, 2H),7.33 (d, 8.7 Hz, 1H), 7.13 (br s, 1H), 7.04 (br d, 8.7 Hz), 4.92 (s,2H), 2.53 (s, 3H).

Triethylamine (42 uL, 0.30 mmol), PyBrOP (70 mg, 0.15 mmole), andcompound e (31 milligrams, 0.075 mmol) were added sequentially to asuspension of N-cyclohexyl-2-amino thiazole (14 milligrams, 0.075 mmol)in acetonitrile (200 uL). The clear brown solution was heated at 100 Cfor 1.5 hours. The reaction was cooled to room temperature and dilutedwith ethyl acetate. The ethyl acetate was washed with water (1×), andbrine (1×) then dried filtered and evaporated to give a crude residuethat was purified by C-18 HPLC (acetonitrile:water, 10:90-100:0,gradient elution over 15 minutes) to give compound f; ¹H-NMR (CDCl₃ 500MHz) δ 7.83 (d, 6.3 Hz, 1H), 7.71 (d, 8.3 Hz, 2H), 7.52 (d, 3.7 Hz, 1H),7.44 (d, 8.3 Hz, 2H), 7.31 (d, 8.7 Hz, 1H), 7.03 (br s, 1H), 6.97 (br d,8.7 Hz, 1H), 4.55 (s, 2H), 4.53 (m, 1H), 2.46 (s, 3H), 1.93 (m, 2H),1.81 (m, 2H), 1.64 (m, 1H), 1.37 (m, 4H), 1.03 (m, 1H), MS (M+1) 576.

EXAMPLE-16

1H NMR (CDCl3): 8.77 (1H, d); 8.30 (1H, d); 8.11 (1H, dd); 7.49 (1H, s);6.98 (1H, dd); 6.65 (1H, d); 6.57 (1H, d); 5.07 (2H, s); 3.88 (3H, s);3.25 (6H, s); 1.35 (9H, s). LCMS (M+H)=394.3.

EXAMPLE 17

¹H NMR (CDCl₃) δ 0.942 (6 H, d), 1.044 (6 H, d), 1.483 (2 H, m), 1.613(4 H, m), 1.683 (1 H, m), 2.449 (3 H, s), 3.395 (4 H, m), 3.840 (3 H,s), 4.817 (2 H, s), 6.605 (1H, s), 6.740 (1 H, d), 7.257 (1 H, d), 7.436(2 H, m), 7.546 (1 H, m), 7.794 (2 H, m).

EXAMPLE 18

¹H NMR (CDCl₃) δ 0.956 (3 H, m), 1.047 (3 H, m), 1.340 (2 H, m), 1.467(2 H, m), 1.578 (2 H, m), 1.704 (2 H, m), 2.487 (3 H, s), 3.399 (4 H,s), 3.837 (3 H, s), 4.869 (2 H, s), 6.642 (1 H, s), 6.747 (1 H, d),7.227 (1 H, d), 7.472 (2 H, m), 7.565 (1 H, m), 7.801 (2 H, m).

EXAMPLE 19

¹H NMR (CDCl₃) δ 0.930 (6 H, d), 1.035 (6 H, d), 1.484 (2 H, m), 1.612(2 H, m), 1.713 (2 H, m), 2.507 (3 H, s), 3.413 (4 H, m), 3.482 (3 H,s), 3.811 (2 H, m), 3,853 (3 H, s), 4.592 (2 H, m), 4.850 (2 H, s),6.636 (1 H, s), 6.765 (1 H, d), 6.860 (1 H, d), 7.303 (1 H, m), 8.037 (1H, d), 8.614 (1 H, s).

EXAMPLE 20

¹H NMR (CDCl₃) δ 0.928 (3 H, t), 0.987 (3 H, t), 1.641 (6 H, m), 1.794(2 H, m), 1.916 (2 H, m), 1.989 (2 H, m), 3.315 (2 H, m), 3.358 (2 H,m), 3.518 (1 H, m), 3.871 (3 H, s), 4.888 (2 H, s), 6.693 (1 H, s),6.947 (1 H, d), 7.734 (1 H, s), 8.322 (1 H, d).

EXAMPLE 21

¹H NMR (CDCl₃) δ 1.321 (12 H, m), 2.738 (2 H, q), 3.855 (3 H, s), 5.002(2 H, s), 6.537 (1 H, s), 6.991 (1 H, d), 7.301 (2 H, d), 7.398 (1 H,s), 7.792 (2 H, d), 8.351 (1 H, d).

EXAMPLE 22

¹H NMR (CDCl₃) δ 1.345 (9 H, s), 3.876 (3 H, s), 5.049 (2 H, s), 6.573(1 H, s), 7.007 (1 H, d), 7.361 (1 H, s), 7.764 (2 H, d), 7.938 (2 H,d), 8.353 (1 H, d).

EXAMPLE 23

¹H NMR (CDCl₃) δ 1.351 (9 H, s), 3.883 (3 H, s), 5.068 (2 H, s), 6.587(1 H, s), 7.022 (1 H, d), 7.344 (2 H, d), 7.401 (1 H, s), 7.911(2 H, d),8.327 (1 H, d).

EXAMPLE 24

¹H NMR (CDCl₃) δ 1.324 (9 H, s), 2.421 (3 H, s), 3.863 (3 H, s), 4.992(2 H, s), 6.557 (1 H, s), 7.008 (1 H, d), 7.180 (1 H, s), 7.294 (2 H,m), 7.366 (1 H, m), 7.459 (1 H, d), 8.323 (1 H, d).

EXAMPLE 25

¹H NMR (CDCI₃) δ 1.292 (9 H, s), 3.771 (3 H, s), 3.833 (3 H, s), 4.911(2 H, s), 6.457 (1H, s), 6.992 (3 H, m), 7.175 (1 H, s), 7.416 (2 H, m),8.314 (1 H, d).

EXAMPLE 26

¹H NMR (CDCl₃) δ 1.328 (9 H, s), 2.455 (3 H, s), 3.867 (3 H, s), 5.043(2 H, s), 6.574 (1 H, s), 6.987 (1 H, d), 7.286 (2 H, m), 7.415 (1 H,s), 7.782 (2 H, d), 8.326 (1 H, s).

EXAMPLE 27

¹H NMR (CDCl₃) δ 1.283 (9 H, s), 2.449 (3 H, s), 3.870 (3 H, s), 5.033(2 H, s), 6.558 (1 H, s), 6.988 (1 H, d), 7.368 (3 H, m), 7.656 (2 H,m), 8.335 (1 H, d).

EXAMPLE 28

¹H NMR (CDCl₃) δ 1.358 (9 H, s), 3.879 (3 H, s), 5.077 (2 H, s), 6.580(1 H, s), 7.020 (1 H, d), 7.294 (1 H, m), 7.405 (1 H, s), 7.650 (1 H,m), 7.701 (1 H, m), 8.292 (1 H, d).

EXAMPLE 29

¹H NMR (CDCl₃) δ 0.909 (3 H, t), 1.012 (3 H, t), 1.610 (4 H, m), 3.328(4 H, m), 3.902 (3 H, s), 4.893 (2 H, s), 6.721 (1 H, s), 6.996 (1 H,d), 7.482 (1 H, s), 7.590 (2 H, d), 7.853 (2 H, d), 8.318 (1 H, d).

EXAMPLE 30

¹H NMR (CDCl₃) δ 1.333 (9 H, s), 3.881 (3 H, s), 5.057 (2 H, s), 6.578(1 H, s), 7.014(1 H, d), 7.382 (1 H, s), 7.576 (2 H, d) 7.846 (2 H, d),8.328 (1 H, d).

EXAMPLE 31

¹H NMR (CDCl₃) δ 1.259 (9 H, s), 3.848 (3 H, s), 4.066 (3 H, s), 5.091(2 H, s), 6.553 (1 H, s), 6.967 (1 H, d), 6.984 (1 H, d), 7.521 (1 H,s), 8.187 (1 H, d), 8.273 (1 H, d), 8.724 (1 H, s).

EXAMPLE 32

¹H NMR (CDCl₃) δ 1.356 (9 H, s), 3.893 (3 H, s), 5.088 (2 H, s), 6.600(1 H, s), 7.029 (1 H, d), 7.506 (4 H, m), 7.901 (1 H, d), 8.100 (2 H,d), 8.271 (1 H, d), 8.376 (1 H, d), 9.173 (1 H, s).

EXAMPLE 33

¹H NMR (CDCl₃) δ 1.353 (9 H, s), 1.647 (2 H, m), 1.796 (2 H, m), 1.926(2 H, m), 2.000 (2 H, m), 3.509 (1 H, m), 3.851 (3 H, s), 5.036 (2 H,s), 6.530 (1 H, s), 6.945 (1 H, d), 7.617 (1 H, s), 8.342 (1 H, d).

EXAMPLE 34

EXAMPLE 35

EXAMPLE 36

EXAMPLE 37

The compounds below are made by modifying Example 35 in a manner knownto those skilled in the art.

Using schemes E, F and G below, the compounds in the tables 7-10 wereprepared:

TABLE 7

Y = O, or S(O)v, and v = 0-2 R is:

TABLE 8

Y = OCH₃, Cl, Br, CH₂CH₃, or CN R is:

TABLE 9

Y = CH₃ or CH₂CH₃ R is:

TABLE 10

Y = OCH₃, CN, or Cl; X = H, or F; Z = Ph, CH(CH₃)₂, CH₂CH(CH₃)₂ R is:

Using scheme H and I, the compounds in table 11 and 12 were prepared.TABLE 11

Wherein R represents:

R₁ represents:

R2 represents: hydrogen or methyl

TABLE 12

Wherein R represents:

R₁ represents:

R2 represents: hydrogen or methyl

Functional Assays

A. Maxi-K Channel

The activity of the compounds can also be quantified by the followingassay.

The identification of inhibitors of the Maxi-K channel is based on theability of expressed Maxi-K channels to set cellular resting potentialafter transfection of both alpha and beta1 subunits of the channel inHEK-293 cells and after being incubated with potassium channel blockersthat selectively eliminate the endogenous potassium conductances ofHEK-293 cells. In the absence of maxi-K channel inhibitors, thetransfected HEK-293 cells display a hyperpolarized membrane potential,negative inside, close to E_(K) (−80 mV) which is a consequence of theactivity of the maxi-K channel. Blockade of the Maxi-K channel byincubation with maxi-K channel blockers will cause cell depolarization.Changes in membrane potential can be determined with voltage-sensitivefluorescence resonance energy transfer (FRET) dye pairs that use twocomponents, a donor coumarin (CC₂DMPE) and an acceptor oxanol(DiSBAC₂(3)).

Oxanol is a lipophilic anion and distributes across the membraneaccording to membrane potential. Under normal conditions, when theinside of the cell is negative with respect to the outside, oxanol isaccumulated at the outer leaflet of the membrane and excitation ofcoumarin will cause FRET to occur. Conditions that lead to membranedepolarization will cause the oxanol to redistribute to the inside ofthe cell, and, as a consequence, to a decrease in FRET. Thus, the ratiochange (donor/acceptor) increases after membrane depolarization, whichdetermines if a test compound actively blocks the maxi-K channel.

The HEK-293 cells were obtained from the American Type CultureCollection, 12301 Parklawn Drive, Rockville, Md., 20852 under accessionnumber ATCC CRL-1573. Any restrictions relating to public access to themicroorganism shall be irrevocably removed upon patent issuance.Transfection of the alpha and beta1 subunits of the maxi-K channel inHEK-293 cells was carried out as follows: HEK-293 cells were plated in100 mm tissue culture treated dishes at a density of 3×10⁶ cells perdish, and a total of five dishes were prepared. Cells were grown in amedium consisting of Dulbecco's Modified Eagle Medium (DMEM)supplemented with 10% Fetal Bovine serum, 1× L-Glutamine, and 1×Penicillin/Streptomycin, at 37° C., 10% CO₂. For transfection withMaxi-K hα(pCIneo) and Maxi-K hβ1(pIRESpuro) DNAs, 150 μl FuGENE™ wasadded dropwise into 10 ml of serum free/phenol-red free DMEM and allowedto incubate at room temperature for 5 minutes. Then, the FuGENE6™solution was added dropwise to a DNA solution containing 25 μg of eachplasmid DNA, and incubated at room temperature for 30 minutes. After theincubation period, 2 ml of the FuGENE6™/DNA solution was added dropwiseto each plate of cells and the cells were allowed to grow two days underthe same conditions as described above. At the end of the second day,cells were put under selection media which consisted of DMEMsupplemented with both 600 μg/ml G418 and 0.75 μg/ml puromycin. Cellswere grown until separate colonies were formed. Five colonies werecollected and transferred to a 6 well tissue culture treated dish. Atotal of 75 colonies were collected. Cells were allowed to grow until aconfluent monolayer was obtained. Cells were then tested for thepresence of maxi-K channel alpha and beta1 subunits using an assay thatmonitors binding of ¹²⁵I-iberiotoxin-D19Y/Y36F to the channel. Cellsexpressing ¹²⁵I-iberiotoxin-D19Y/Y36F binding activity were thenevaluated in a functional assay that monitors the capability of maxi-Kchannels to control the membrane potential of transfected HEK-293 cellsusing fluorescence resonance energy transfer (FRET) ABS technology witha VIPR instrument. The colony giving the largest signal to noise ratiowas subjected to limiting dilution. For this, cells were resuspended atapproximately 5 cells/ml, and 200 μl were plated in individual wells ina 96 well tissue culture treated plate, to add ca. one cell per well. Atotal of two 96 well plates were made. When a confluent monolayer wasformed, the cells were transferred to 6 well tissue culture treatedplates. A total of 62 wells were transferred. When a confluent monolayerwas obtained, cells were tested using the FRET-functional assay.Transfected cells giving the best signal to noise ratio were identifiedand used in subsequent functional assays.

For functional assays:

The transfected cells (2E+06 Cells/mL) are then plated on 96-wellpoly-D-lysine plates at a density of about 100,000 cells/well andincubated for about 16 to about 24 hours. The medium is aspirated of thecells and the cells washed one time with 100 μl of Dulbecco's phosphatebuffered saline (D-PBS). One hundred microliters of about 9 μM coumarin(CC₂DMPE)-0.02% pluronic-127 in D-PBS per well is added and the wellsare incubated in the dark for about 30 minutes. The cells are washed twotimes with 100 μl of Dulbecco's phosphate-buffered saline and 100 μl ofabout 4.5 μM of oxanol (DiSBAC₂(3)) in (mM) 140 NaCl, 0.1 KCl, 2 CaCl₂,1 MgCl₂, 20 Hepes-NaOH, pH 7.4, 10 glucose is added. Three micromolar ofan inhibitor of endogenous potassium conductance of HEK-293 cells isadded. A maxi-K channel blocker is added (about 0.01 micromolar to about10 micromolar) and the cells are incubated at room temperature in thedark for about 30 minutes.

The plates are loaded into a voltage/ion probe reader (VIPR) instrument,and the fluorescence emission of both CC₂DMPE and DiSBAC₂(3) arerecorded for 10 sec. At this point, 100 μl of high-potassium solution(mM): 140 KCl, 2 CaCl₂, 1 MgCl₂, 20 Hepes-KOH, pH 7.4, 10 glucose areadded and the fluorescence emission of both dyes recorded for anadditional 10 sec. The ratio CC₂DMPE/DiSBAC₂(3), before addition ofhigh-potassium solution equals 1. In the absence of maxi-K channelinhibitor, the ratio after addition of high-potassium solution variesbetween 1.65-2.0. When the Maxi-K channel has been completely inhibitedby either a known standard or test compound, this ratio remains at 1. Itis possible, therefore, to titrate the activity of a Maxi-K channelinhibitor by monitoring the concentration-dependent change in thefluorescence ratio.

The compounds of this invention were found to causeconcentration-dependent inhibition of the fluorescence ratio with IC₅₀'sin the range of about 1 nM to about 20 μM, more preferably from about 10nM to about 500 nM.

B. Electrophysiological Assays of Compound Effects on High-ConductanceCalcium-Activated Potassium Channels

Methods:

Patch clamp recordings of currents flowing through large-conductancecalcium-activated potassium (maxi-K) channels were made from membranepatches excised from CHO cells constitutively expressing the α-subunitof the maxi-K channel or HEK293 cells constitutively expressing both α-and β-subunits using conventional techniques (Hamill et al., 1981,Pflügers Archiv. 391, 85-100) at room temperature. Glass capillarytubing (Garner #7052 or Drummond custom borosilicate glass 1-014-1320)was pulled in two stages to yield micropipettes with tip diameters ofapproximately 1-2 microns. Pipettes were typically filled with solutionscontaining (mM): 150 KCl, 10 Hepes (4-(2-hydroxyethyl)-1-piperazinemethanesulfonic acid), 1 Mg, 0.01 Ca, and adjusted to pH 7.20 with KOH.After forming a high resistance (>10⁹ ohms) seal between the plasmamembrane and the pipette, the pipette was withdrawn from the cell,forming an excised inside-out membrane patch. The patch was excised intoa bath solution containing (mM): 150 KCl, 10 Hepes, 5 EGTA (ethyleneglycol bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid), sufficientCa to yield a free Ca concentration of 1-5 μM, and the pH was adjustedto 7.2 with KOH. For example, 4.193 mM Ca was added to give a freeconcentration of 1 μM at 22° C. An EPC9 amplifier (HEKA Elektronic,Lambrect, Germany) was used to control the voltage and to measure thecurrents flowing across the membrane patch. The input to the headstagewas connected to the pipette solution with a Ag/AgCl wire, and theamplifier ground was connected to the bath solution with a Ag/AgCl wirecovered with a tube filled with agar dissolved in 0.2 M KCl. Theidentity of maxi-K currents was confirmed by the sensitivity of channelopen probability to membrane potential and intracellular calciumconcentration.

Data acquisition was controlled by PULSE software (HEKA Elektronic) andstored on the hard drive of a MacIntosh computer (Apple Computers) forlater analysis using PULSEFIT (HEKA Elektronic) and Igor (Wavemetrics,Oswego, Oreg.) software.

Results:

The effects of the compounds of the present invention on maxi-K channelswas examined in excised inside-out membrane patches with constantsuperfusion of bath solution. The membrane potential was held at −80 mVand brief (100-200 ms) voltage steps to positive membrane potentials(typically +50 mV) were applied once per 15 seconds to transiently openmaxi-K channels. As a positive control in each experiment, maxi-Kcurrents were eliminated at pulse potentials after the patch wastransiently exposed to a low concentration of calcium (<10 nM) made byadding 1 mM EGTA to the standard bath solution with no added calcium.The fraction of channels blocked in each experiment was calculated fromthe reduction in peak current caused by application of the specifiedcompound to the internal side of the membrane patch. Compound wasapplied until a steady state level of block was achieved. K_(I) valuesfor channel block were calculated by fitting the fractional blockobtained at each compound concentration with a Hill equation. The K_(I)values for channel block by the compounds described in the presentinvention range from 0.01 nM to greater than 10 μM.

1. A compound of the structural formula I:

or a pharmaceutically acceptable salt, enantiomer, diastereomer ormixture thereof: wherein, R represents hydrogen, or C₁₋₆ alkyl; R₁represents hydrogen or C₁₋₆ alkyl, CF₃, C₁₋₆ alkoxy, COR^(c), CO₂R₈,CONHCH₂CO₂R, N(R)₂, said alkyl and alkoxy optionally substituted with1-3 groups selected from R^(b); X represents —(CHR₇)_(p)—; Y is notpresent, —CO(CH₂)_(n)—, or —CH(OR)—; Q represents N, CR^(y), or O,wherein R₂ is absent when Q is O; R^(y) represents H, or C₁₋₆ alkyl;R_(w) represents H, C₁₋₆ alkyl, —C(O)C₁₋₆ alkyl, —C(O)OC₁₋₆ alkyl,—SO₂N(R)₂, —SO₂C₁₋₆ alkyl, —SO₂C₆₋₁₀ aryl, NO₂, CN or —C(O)N(R)₂; R₂represents hydrogen, C₁₋₁₀ alkyl, C₁₋₆ alkylSR, —(CH₂)_(n)O(CH₂)_(m)OR,—(CH₂)_(n)C₁₋₆ alkoxy, —(CH₂)_(n)C₃₋₈ cycloalkyl, —(CH₂)_(n)C₃₋₁₀heterocyclyl, —(CH₂)_(n)C₅₋₁₀ heteroaryl, —N(R)₂, —COOR, or—(CH₂)_(n)C₆₋₁₀ aryl, said alkyl, heterocyclyl, aryl or heteroaryloptionally substituted with 1-3 groups selected from R^(a); R₃represents hydrogen, C₁₋₁₀ alkyl, —(CH₂)_(n)C₃₋₈ cycloalkyl,—(CH₂)_(n)C₃₋₁₀ heterocyclyl, —(CH₂)_(n)C₅₋₁₀ heteroaryl,—(CH₂)_(n)COOR, —(CH₂)_(n)C₆₋₁₀ aryl, —(CH₂)_(n)NHR₈, —(CH₂)_(n)N(R)₂,—(CH₂)_(n)NHCOOR, —(CH₂)_(n)N(R₈)CO₂R, —(CH₂)_(n)N(R₈)COR,—(CH₂)_(n)NHCOR, —(CH₂)_(n)CONH(R₈), aryl, —(CH₂)_(n)C₁₋₆ alkoxy, CF₃,(CH₂)_(n)SO₂R, —(CH₂)_(n)SO₂N(R)₂, —(CH₂)_(n)CON(R)₂,—(CH₂)_(n)CONHC(R)₃, —(CH₂)_(n)COR₈, nitro, cyano or halogen, saidalkyl, alkoxy, heterocyclyl, aryl or heteroaryl optionally substitutedwith 1-3 groups of R^(a); or, when Q is N, R₂ and R₃ taken together withthe intervening N atom form a 4-10 membered heterocyclic carbon ringoptionally interrupted by 1-2 atoms of O, S, C(O) or NR, and optionallyhaving 1-4 double bonds, and optionally substituted by 1-3 groupsselected from R^(a); R⁴ and R⁵ independently represent hydrogen, C₁₋₆alkoxy, OH, C₁₋₆ alkyl, COOR, SO₃H, O(CH₂)_(n)N(R)₂, O(CH₂)_(n)CO₂R,C₁₋₆ alkylcarbonyl, S(O)qR^(y), OPO(OH)₂, CF₃, N(R)₂, nitro, cyano orhalogen; R₆ represents hydrogen, C₁₋₁₀ alkyl, —(CH₂)_(n)C₆₋₁₀ aryl,—(CH₂)_(n)C₅₋₁₀ heteroaryl, (C₆₋₁₀ aryl)O—, —(CH₂)_(n)C₃₋₁₀heterocyclyl, —(CH₂)_(n)C₃₋₈ cycloalkyl, —COOR, —C(O)CO₂R, said aryl,heteroaryl, heterocyclyl and alkyl optionally substituted with 1-3groups selected from R^(a); R⁷ represents hydrogen, C₁₋₆ alkyl,—(CH₂)_(n)COOR or —(CH₂)_(n)N(R)₂, R⁸ represents —(CH₂)_(n)C₃₋₈cycloalkyl, —(CH₂)_(n 3-10) heterocyclyl, C₁₋₆ alkoxy or —(CH₂)_(n)C₅₋₁₀heteroaryl, said heterocyclyl, aryl or heteroaryl optionally substitutedwith 1-3 groups selected from R^(a); R^(a) represents F, Cl, Br, I, CF₃,N(R)₂, NO₂, CN, —COR₈, —CONHR₈, —CON(R₈)₂, —O(CH₂)_(n)COOR,—NH(CH₂)_(n)OR, —COOR, —OCF₃, —NHCOR, —SO₂R, —SO₂NR₂, —SR, (C₁-C₆alkyl)O—, —(CH₂)_(n)O(CH₂)_(m)OR, —(CH₂)_(n)C₁₋₆ alkoxy, (aryl)O—, —OH,(C₁-C₆ alkyl)S(O)_(m)—, H₂N—C(NH)—, (C₁-C₆ alkyl)C(O)—, (C₁-C₆alkyl)OC(O)NH—, —(C₁-C₆ alkyl)NR_(w)(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w),—(C₁-C₆ alkyl)O(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —(C₁-C₆alkyl)S(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —(C₁-C₆ alkyl)-C₃₋₁₀heterocyclyl-R_(w), —(CH₂)_(n)-Z¹-C(=Z²)N(R)₂, —(C₂₋₆alkenyl)NR_(w)(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —(C₂₋₆alkenyl)O(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —(C₂₋₆alkenyl)S(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —(C₂₋₆ alkenyl)-C₃₋₁₀heterocyclyl-R_(w), —(C₂₋₆ alkenyl)-Z¹-C(=Z²)N(R)₂, —(CH₂)_(n)SO₂R,—(CH₂)_(n)SO₃H, —(CH₂)_(n)PO(OR)₂, cyclohexyl, morpholinyl, piperidyl,pyrrolidinyl, thiophenyl, phenyl, pyridyl, imidazolyl, oxazolyl,isoxazolyl, thiazolyl, thienyl, furyl, isothiazolyl, C₂₋₆ alkenyl, andC₁-C₁₀ alkyl, said alkyl, alkenyl, alkoxy, phenyl, pyridyl, imidazolyl,oxazolyl, isoxazolyl, thiazolyl, thienyl, furyl, and isothiazolyloptionally substituted with 1-3 groups selected from C₁-C₆ alkyl, CN,(CH₂)_(n)tetrazolyl, COOR, SO₃H, OH, F, Cl, Br, I,—O(CH₂)_(n)CH(OH)CH₂SO₃H, and

Z¹ and Z² independently represents NR_(w), O, CH₂, or S; R^(b)represents C₁₋₆ alkyl, —COOR, —SO₃R, —OPO(OH)₂, —(CH₂)_(n)C₆₋₁₀ aryl, or—(CH₂)_(n)C₅₋₁₀ heteroaryl; R^(c) represents hydrogen, C₁₋₆ alkyl, or—(CH₂)_(n)C₆₋₁₀ aryl; m is 0-3; n is 0-3; q is 0-2; and p is0-1.
 2. Acompound of the structural formula I wherein X represents CHR₇.
 3. Acompound according to claim 1 wherein Y is —CO(CH₂)_(n).
 4. A compoundaccording to claim 1 wherein Y is CH(OR).
 5. A compound according toclaim 1 wherein Q is N.
 6. A compound according to claim 1 wherein Q isCH.
 7. A compound according to claim 2 wherein R₆ is (CH₂)_(n)C₆₋₁₀aryl, (CH₂)_(n)C₅₋₁₀ heteroaryl, (CH₂)_(n)C₃₋₁₀ heterocyclyl, or(CH₂)_(n)C₃₋₈ cycloalkyl, said aryl, heteroaryl, heterocyclyl and alkyloptionally substituted with 1 to 3 groups of R^(a).
 8. A compoundaccording to claim 6 wherein R₇ is hydrogen or C₁₋₆ alkyl.
 9. A compoundaccording to claim 6 wherein Q is N and n is
 0. 10. A compound accordingto claim 1 wherein Y is —CO(CH₂)_(n), Q is N, n is 0, R₂ is C₁₋₁₀ alkylor C₁₋₆ alkylOH and R₃ is (CH₂)_(n)C₃₋₁₀ heterocyclyl, said heterocyclyland alkyl optionally substituted with 1 to 3 groups of R^(a).
 11. Acompound selected from Tables 1 through 14 which is: TABLE 1

Wherein R represents:

and R* represents:

or hydrogen;

TABLE 2

Wherein R represents:

R* represents:

or hydrogen and R{circumflex over ( )} represents hydrogen or methyl;

TABLE 3

Wherein R represents:

R* represents:

or chlorine and R{circumflex over ( )} represents hydrogen or methyl;

TABLE 4

R represents methyl or methoxy and R* represents methyl, H or COCH;

R′ represents methyl or methoxy; R{circumflex over ( )} representshydrogen or COOEt; R′′′ represents COOH or COOtBu; a R″ represents:COOMe, H, COOH, or

TABLE 5

R* represents hydrogen or methyl; R^(y) represents methyl or CF₃;

R represents methyl, (CH2)₂SCH₃,

R{circumflex over ( )} represents:

R+ represents: (CH₂)₂CO₂H, chlorine,

TABLE 6

Wherein n represents 1-2; R{circumflex over ( )} represents hydrogen ormethyl R represents:

and R′ represents: chlorine,

TABLE 7

Y = O, or S(O)R and p = 0-2 R is:

TABLE 8

Y = OCH₃, Cl, Br, CH₂CH₃, or CN R is:

TABLE 9

Y = CH₃ or CH₂CH₃ R is:

TABLE 10

Y = OCH₃, CN, or Cl; X = H, or F; Z = Ph, CH(CH₃)₂, CH₂CH(CH₃)₂ R is:

TABLE 11

Wherein R represents:

R₁ represents:

R2 represents: hydrogen or methyl

TABLE 12

Wherein R represents:

R₁ represents:

R2 represents: hydrogen or methyl

TABLE 13

TABLE 14

or a pharmaceutically acceptable salt, enantiomer, diastereomer ormixture thereof.
 12. A method for treating ocular hypertension orglaucoma comprising administration to a patient in need of suchtreatment a therapeutically effective amount of a compound of claim 1.13. The method according to claim 12 wherein the compound of formula Iis applied as a topical formulation selected from solution topicalformulation and a suspension topical formulation.
 14. A method accordingto claim 13 in which the topical formulation optionally contains xanthangum or gellan gum.
 15. A method according to claim 13 wherein an activeingredient belonging to the group consisting of: δ-adrenergic blockingagent, parasympathomimetic agent, EP4 agonist, carbonic anhydraseinhibitor, and a prostaglandin or a prostaglandin derivative isoptionally added to the formulation.
 16. A method according to claim 15wherein the δ-adrenergic blocking agent is timolol; theparasympathomimetic agent is pilocarpine; the carbonic anhydraseinhibitor is dorzolamide, acetazolamide, metazolamide or brinzolamide;the prostaglandin is latanoprost or rescula, and the prostaglandinderivative is a hypotensive lipid derived from PGP2α prostaglandins. 17.A method for treating macular edema, macular degeneration, increasingretinal and optic nerve head blood velocity, increasing retinal andoptic nerve oxygen tension, and/or providing a neuroprotective effectcomprising administration to a patient in need of such treatment apharmaceutically effective amount of a compound of claim 1; or apharmaceutically acceptable salt, enantiomer, diastereomer or mixturethereof.
 18. The method according to claim 17 wherein the compound offormula I is applied as a topical formulation.
 19. A method according toclaim 18 in which the topical formulation optionally contains xanthangum or gellan gum.
 20. A method of preventing repolarization orhyperpolarization of a mammalian cell wherein the cell contains apotassium channel comprising the administration to a mammal, including ahuman, in need thereof, of a pharmacologically effective amount of acompound according to claim 1, or a pharmaceutically acceptable salt,enantiomer, diastereomer or mixture thereof
 21. A method of treatingAlzheimer's Disease, depression, cognitive disorders, arrhythmiadisorders and/or diabetes in a patient in need thereof comprisingadministering a pharmaceutically effective amount of a compoundaccording to claim 1, or a pharmaceutically acceptable salt, enantiomer,diastereomer or mixture thereof.